This proposal constitutes a cross-cultural cohort study of seven defined representative populations of adolescent subjects in order to quantitate and evaluate demographic, psycho-social, dietary and lipid variables which may contribute to later coronary heart disease (CHD) risk. The study cohorts have been chosen to permit comparisons between adolescents residing in a country of highest and lowest CHD incidence (USA and Greece, respectively), those who live in rural and urban areas (rural-urban transition), and adolescents who were born in the country of low incidence, but who have immigrated with their parents and are exposed to the socio-nutritional environment of the high CHD incidence country. The endpoints of the study are of a "risk factor" nature, that is the "tracking" of lipid variables for a period of three years for three different age groups in order to include what is hypothesized to be a critical period in the pathogenesis of coronary arteriosclerosis (i.e., ages 9 through 17). A nexus will be effected between the lipid and other variable status of the study subjects, with sub-population, age-matched, geography-matched individuals who died accidentally, from whom coronary and aorta arterial tissue will be assessed for type and degree of fatty streaks and fibrous and/or arteriosclerotic vessel involvement. This study will not only serve to Study associations between cohort subjects and their early CHD risk factor status, but will seek to develop an integrative assessment of how the host and environmental variables studied may contribute to, or protect against later CHD risk. Finally, it is also aspired that new hypotheses regarding intervention strategies in childhood and adolescence may be developed which prevent adult CHD.